Overview of Shar-Pei Fever
Shar-pei fever is also referred to as Familial Shar-pei Fever and Swollen Hock Syndrome. The disorder is believed to be caused by abnormal regulation of the immune system and is an inherited disorder.
This is a disease of the shar-pei breed and shar-pei mixes, and can affect either sex. Signs often begin in dogs younger than 18 months, but may be seen in older dogs as well.
Shar-pei fever, as implied by the name, is characterized by recurrent fever episodes. This may be accompanied by inflammation of multiple joints. Dogs with shar-pei fever are at an increased risk of developing kidney failure or significant liver disease later in life.
What to Watch For
Lameness or stiff gait
Swelling of joints, particularly in the hind legs
Apparent pain and reluctance to move
Diagnosis of Shar-Pei Fever
Tests to diagnosis Shar-Pei Fever may include:
History and physical exam
Complete blood count (CBC)
Urinalysis and urine culture
Urine protein/creatinine ratio
Chest and abdominal x-rays
X-rays of swollen joints
Blood tests for tick-borne disease
Immune system tests
Kidney or liver biopsy (in certain cases)
Treatment of Shar-Pei Fever
Treatment will vary depending on severity of the disorder.
Intravenous fluid therapy and supportive care may be required during fever episodes.
Non-steroidal anti-inflammatory drugs for pain and lameness.
Treatment with a drug called colchicine may reduce frequency and severity of fevers, as well as help prevent future kidney and liver disease.
Low protein diet
Supportive care for dogs in kidney failure
Home Care and Prevention
Give all medications as prescribed by your veterinarian. Monitor your dog’s body temperature at home if clinical signs of illness are present.
Because this is an inherited disorder, affected dogs should never be used for breeding.
In-depth Information on Shar-Pei Fever
Shar-pei fever is a disorder that resembles familial Mediterranean fever of humans. The initial stages of the disease are characterized by recurrent episodes of fever that last approximately 24 to 36 hours. The first episodes are typically seen in young adult dogs. Roughly half of the dogs also suffer swelling in and around joints, most commonly the hock, which is equivalent to the human ankle joint. Many dogs are lethargic secondary to the fever, and may have a reduced appetite. Even if joint swelling is not seen, dogs may be stiff or lame, and may be reluctant to move. Less commonly, they may have swelling and pain associated with the muzzle, or abdominal pain, vomiting and diarrhea.
The fevers are believed to be associated with an elevation of a cytokine called Interleukin-6 (IL-6). Interleukin is a substance produced by white blood cells and other cells in the body, which promotes an inflammatory response. Dysregulation of the immune system is thought to be the cause of the elevated IL-6 levels.
IL-6 production leads to production of inflammatory proteins, which in turn leads to production of an abnormal protein called amyloid. Amyloid accumulates in the body and is eventually deposited in multiple organs. The organs most commonly affected include the kidneys and liver. This in turn may result in kidney and liver failure.
Many dogs with a history of recurrent fevers develop kidney failure between the ages of 3 and 5 years. Clinical liver disease is less common, although it has been reported. Dogs in kidney failure may experience weight loss, vomiting, diarrhea, loss of appetite, increased thirst, and increased urination.
Other diseases may cause clinical signs similar to those seen with shar-pei fever. These include:
Systemic lupus erythematosus (SLE). This is an autoimmune, or immune-mediated disease in which the body attacks its own cells. Joint inflammation, lameness, kidney disease, and fever are common manifestations of SLE.
Immune-mediated polyarthritis. This is another immune-mediated disease, which is limited to joint inflammation. Dogs may have a fever but do not have involvement of other organs.
Septic arthritis. Infection of one or more joints could cause similar clinical signs. Most joint infections are limited to one joint, whereas shar-pei fever usually involves multiple joints.
Tick-borne disease. Infectious diseases spread by ticks may cause joint inflammation, lameness, fever, and even kidney disease, among other signs. These include Lyme disease, Ehrlichia and Rocky Mountain spotted fever.
Rheumatoid arthritis. This is an autoimmune disease that causes bony destruction of joints. The swelling associated with shar-pei fever does not cause bony lesions, but the clinical signs may be similar.
Severe bacterial infection. A bacterial infection such as pneumonia, endocarditis (infection of a heart valve), urinary tract infection, abscess, or other sites of infection in the body will commonly cause fever, pain, and reluctance to move. Secondary inflammation of the joints may also occur in some cases.
Neoplasia (cancer). Although less likely in dogs less than two years of age, cancer can cause fever and discomfort, mimicking the signs of shar-pei fever.
In-depth Information on Diagnosis
A history and physical exam are always important to obtain an accurate clinical picture and choose appropriate diagnostic tests. Owners may report previous episodes of illness and fever, since this is a disease that recurs.
Additional tests that may be recommended include:
Complete blood count (CBC). The CBC evaluates the red and white blood cells as well as the platelets. Many dogs with shar-pei fever will have elevations of the white blood cell count.
Biochemical profile. The biochemical profile helps to evaluate liver and kidney function as well as assessing blood sugar, protein and electrolyte levels (sodium and potassium are examples of electrolytes). Affected dogs may show elevated globulin levels. Globulins are proteins that become elevated in the face of inflammation. Dogs with early disease do not show other abnormalities on the biochemical profile. Dogs suffering from kidney and/or liver damage have elevations of kidney and liver parameters. This blood test is an important marker for indicating disease status and progression.
Urinalysis and culture. Analysis of the urine provides further information about kidney function. Dogs with significantly impaired kidney function have dilute urine and may have excessive protein in the urine. Bacterial culture of a urine sample is warranted to rule out a urinary tract infection.
Urine protein/creatinine ratio. This test is used to quantify the amount of protein in the urine and is an important indicator of a certain type of kidney damage that may be seen secondary to amyloid deposition in the kidneys.
Blood culture. Bacterial culture of the blood during a high fever helps to rule out the likelihood of an infection within the bloodstream.
Chest and abdominal x-rays. These tests are often normal in dogs with shar-pei fever. They are nevertheless important tests to rule out other diseases, such as pneumonia and other infections.
X-rays of joints. Dogs that present with swollen hocks show evidence of soft tissue swelling on x-rays, but no bony abnormalities.
Joint taps. Small amounts of fluid can be obtained from the affected joints. Characterization of cell types within the fluid may rule out certain diseases. Culture of the fluid is recommended to rule out bacterial infection. This test is not used as a specific indicator of shar-pei fever because joint inflammation due to various causes may have similar cell types in the joint fluid. Some dogs with shar-pei fever have normal fluid analyses.
Blood tests for tick-borne disease. Antibodies in the blood can be measured to test for the possibility of the aforementioned infectious diseases that are spread by ticks.
Immune system tests. If SLE or rheumatoid arthritis is suspected, special blood tests can be performed to help confirm the diagnosis. These are called the Antinuclear Antibody Test (ANA), and Rheumatoid Factor.
Kidney or liver biopsy. In dogs showing evidence of kidney or liver dysfunction, biopsies of these organs may be considered to confirm a diagnosis of amyloid deposition. In many cases the dogs have had a history of shar-pei fever, and the subsequent development of kidney or liver disease is presumed to be due to amyloid, even without biopsy confirmation.
In-depth Information on Therapy
The main goal of therapy in dogs with shar-pei fever is to reduce the risk of secondary kidney or liver disease in patients suffering from the signs of recurring fever and lameness. In most cases the fever episodes are short-lived and do not cause prolonged illness. Sometimes however, the fevers can be quite high, and may require hospitalization.
In dogs with temperatures greater than 106 degrees Fahrenheit, there is a risk of cell damage secondary to the excess body heat. These patients need to be hospitalized and treated with IV fluids. If there is any indication of concurrent bacterial infection, antibiotic therapy is also warranted. In most cases there are no infections, and antibiotics do not help.
Non-steroidal anti-inflammatory drugs may be used to relieve pain and lameness associated with the episodes of fever and joint swelling. They may also reduce the fever. This class of drugs must be used carefully in veterinary patients to avoid undesired side effects. They should only be used under the direct supervision of your veterinarian.
Colchicine is a special drug used in humans with a similar disorder. When used early in the course of the disease, this drug helps reduce the frequency of fever episodes, as well as reducing the likelihood of amyloid deposition and secondary kidney or liver failure. Use of colchicine in patients with established kidney failure may or may not be helpful, and may increase risk of drug toxicity. This drug is not approved for use in dogs and may cause severe side effects including vomiting and diarrhea, as well as bone marrow suppression. This is another drug that should only be used under direct supervision of your veterinarian, and must be handled carefully by humans.
A low protein diet may be helpful in slowing down development of kidney disease in dogs with recurrent fever episodes.
Supportive therapy should be provided for dogs already showing signs of kidney failure. This may include fluid therapy, use of anti-ulcer medication, strict dietary regimens, use of anti-nausea drugs, blood pressure monitoring, and use of a drug to reduce protein loss through the kidneys (not all dogs have protein-losing kidney disease).
Follow-up Care for Dogs with Shar-Pei Fever
Optimal treatment for your dog involves a combination of home and professional veterinary care. Follow-up can be critical, especially if your dog does not rapidly improve.
Administer all prescribed medications as directed. Alert your veterinarian if you are having problems treating your dog, or if adverse side effects are noted.
Frequent monitoring of complete blood counts is important for patients treated with colchicine. Initial evaluation should be carried out every two weeks.
Patients in kidney failure also require careful and frequent monitoring of weight, kidney values, blood pressure, blood protein levels, and red blood cell counts.
Unfortunately this is not a curable disease, and close contact with your veterinarian will be necessary to optimize treatment and keep your pet as comfortable as possible.
Ultimately most patients with recognized shar-pei fever die of kidney failure within several years.